Mechanical stoker



.INVENTO s [ad rk/75M ATTORNEYS 4 Sheets-Sheet 1 March Z3 1926. A

c. s. DAvY ET AL MECHANICAL STOKER Filed July', 1921 C. S. DAVY ET ALMarch 23 1926.

MECHANICAL STOKER Filed July 6, 1921 4 Sheets-Sheet 2 INvE ToRs BY I6701/ @641/ M /m/ATTORNEYS v 1,578,016 c; s. DAvY ETIAL A March 23 1926MECHANICAL STOKER 4 Sheets-Sheet B Filed July 6, 1921 March 23, 1926.

- v c. s. DAvY ET AL MECHANICAL STOKER Filed July', 1921 V 4Sheets-Sheet 4 ATToRNl-:Y

iatented Mar. 23, i926.

UNITED STATES PATENT OFFICE.

CHRISTOPHER SAMUEL DAVY, OF DULWIGH, AND ARTHUR SPYER, OF LONDON, ENG-LAND, ASSIGNORS T0 THE BABCOCK @t WILCOX COMPANY, OF BAYONNE, NEWJERSEY, A CORPORATION OF NEW JERSEY. i

MECHANICAL STOKER.

Application filed July 6,

T0 all whom it may concern:

Be it known that we, CHRISTOPHER SAM- URL Davy and ARTHUR SPYER,subjects of the King of Great Britain, and residing at 162. RosendaleRoad, Dulwich, London, S. E. 21, England, and 14 Clarendon Court., MaidaVale, London, England, respectively. have invented certain new and.useful Improvements in Mechanical Stokers, of which the following is aspecification.

This invention relates to improvements in and connected with mechanicalstokers, and has for its object to improve the emciency of a furnacefitted with such stokers by providing it with a simple and reliablemeans for effecting acontrolied pressure air supply, and with mechanicalmeans adapted, while the pressure air supply is in operation, to dealwith the fuel riddlings and waste ash, the arrangement preferably beingsuch that the grate may be run simultaneously on natural draught, ifrequired.

The invention is illustrated in the accompanying drawings in which Fig.lv is a llongitudinal section, Fig. 2 a cross section and Fig. 3 a planshowing the apparatus applied to a chain grate stoker of the Babcock &lVilcoX type, a part of the chain being removed, and Fig. 4 is alongitudinal section of a modified form of apparatus.

In the arrangement shown in Figs. 1, 2, and 3, the apparatus is disposedbetween the Aupper and lower runs of the revolving chain of themechanical stoker, while in the arrangement shown in Fig. 4, part of theapparat-us is disposed between the runs of the revolving chain, and partdisposed on the outside of the bottom and front portion of the revolvingchain.

Referring to the drawings, it will be seen that a plurality of chambersor compartments A for distributing the air under pressure, are provided.but there may be only one chamber, or one chamber may be divided into asmany chambers as thought necessary, according to the installation. Theair under pressure is supplied from the main trunk A4, through branchesA3, all of which have openings A2 into the chambers A. The branches A3are fitted with dampers A5 to regulate the air pressure in the chambersA. After the air is supplied to chambers A the air distributes itself tothe underside of the valve member C is preferably provided with aplurality of radial vanes, here illustrated as four in number, soarranged that two opposite vanes always engage the valve seat, therebyalways maintaining the air chamber or chambers sealed. Valve C is drivennie-- chanically by means of a rotating shaft C from a geared wheel C4,the latter being driven by the geared wheel D1, which Ais rotated by acountershaft D, the countershaft D being driven from the front chaingrate, driving shaft E by means of bevel wheels El and D2. The force ofthe entering air carries the riddlings transversely over the plate A13,located above the lower run of Vthe chain to the rotary discharge memberwhich is sealed against said plate. The riddlings are thus collected inthe pockets formed between the vanes of the rotary member whichdischarges them through the opening C2, from which they are deposited onthe lower run of the chain and either sift therethrough or are carriedto the forward end of the grate where the surface of the chain is brokenthereby forming openings between adjacent links in passing over thefront sprocket wheels, forming openings through which the residualriddlings fall.

The valve may be fitted either parallel to the axis of the chambers A,as in Figs. l and 2, or transverse thereto as in Fig. 4.

In Fig. 4 is shown an alternative arrangement of pressure draught andriddling deposit apparatus, part of which is placed within the revolvingchain grate B, and part below the bottom and front side of chain grateB.

In this figure only one pressure air chamber Al is shown, but this maybe divided into several compartments, and the high pressure air supplymay enter into the said chambers by any suitable place or places.,according to the installation required.

To render air chamber Al suitable tor high pressure air draught, and atthe same time to deal with the riddlings and waste ash, sealing platesA7 and A8 are arranged behind the iront driving shaft and in front oi"Athe rear shaft. A plate A9, disposed below the underside ot chain B oithe Stoker, is connected up by plates A19 and A11 and a door A12 to thestoker hopper, the door being placed at the front for inspection, or forrunning on natural draught. Vln the form shown in Fig. l, the riddlingspass through the lower run ot the chain grate and are carried along onthe plate A9 until they are discharged into the valves C5.

To the plates A7 and A9 are attached the plates F and F', which lie onthe upper side orn the bottom portion of the chain B, thereby eifectingan air seal with the bottom plate A9.

rThe pressure air supply chamber A delivers and distributes its airequally through the openings AG into the fuel bed which is carried onthe up 3er surface ot the chain The plate A9 serves a further purpose,viz, to divide and deliver the riddlings from the waste ashes which tallthrough the chain grate, while the latter is in operation, to theirrespective destinations. For this purpose the plate A9 is divided intothree parts, to which are i' vVed two revolving valves C9 adapted to bedriven from the driving shaft of the chain grate stoker.

The plate A9 with its valve C5 at the rear of the stoker collects anddelivers ash through the valve U5 into the ash-pit G. The center plateA9 collects all the riddlings which drop through the grate B and arecarried forward by the bottom chain B until they reach the front valveC5, where they are delivered by said valve C5 into the riddling pit l-l,'trom which they are carried back for retiring onto the stoker.

What we claim and desire to secure by Letters Patent of the UnitedStates is l. In combination, a chain grate Stoker, a compartmentassociated therewith communicating with the under side of the upper runoit' said vchain grate, means for supplying air under pressure to saidcompartment, and a discharge member associated with said compartmentconstructed and arranged to discharge riddlings therefrom and maintainthe compartment sealed during operation.

2. In combination, a chain grate stoker, a compartment associatedtherewith communicating with the under side of the upper run of saidchain grate, means for supplying air under pressure to said compartment,and a discharge member associated with said compartment and actuated bythe gratedriving mechanism for discharging riddlings trom saidcompartment and constructed and arranged to maintain the saidcompartment sealed during normal operation.

3. 1n combination, a chain grate stoker, a compartment associatedtherewith communicating with the under side of the upper run ot saidchain grate, means for supplying air under pressure to said compartment,and a rotary discharge member associated with said compartment fordischarging riddlings therefrom, and constructed and arranged tomaintain said compartment sealed during operation ot' said member.

4. In combination, chain grate Stoker, a compartment associatedtherewith communicating with the under side of the upper run of saidchain grate, means Jfor supplying air-under pressure to saidcompartment, a valve member comprising a rotary valve actuated by thegrate-driving mechanism and provided with a plurality of radial vanes,and a valve seat for said valve provided with discharge openings fordischarging riddlings from said chain grate, the valve member beingconstructed and arranged so that opposite vanes always engage said valveseat to maintain said compartment sealed.

5. In combination, a chain grate Stoker, a compartment located betweenthe upper and lower runs of said stoker and communicating with the lowerside of the upper run, means tor supplying air under pressure tosaidcompartment, and a discharge member associated with said compartmentconstructed and arranged to discharge riddlings therektrom and maintainthe compartment sealed during operation.

6. In combination, a chain grate Stoker, a compartment located betweenthe upper and lower runs oi' said stoker and communicating with thelower side of the upper run, means for supplying air under pressure tosaid compartment, a discharge member located at one side of saidcompartment sealed during normal operation and constructed and arrangedto discharge riddlings from said compartment and maintain thecompartment sealed during operation, and means for admitting air underpressure to the side of said compartment opposite said discharge member.

7. 1n combination, a chain grate stoker, a compartment located betweenthe upper and lower runs of said stoker and communicating with the lowerside or" the upper run and comprising a plate located above the lowerrun of the chain grate, means for supplying air under pressure at oneside of said compartment and grate, a discharge member located at theother side of said grate extending longitudinally thereof and sealedagainst said plate, said member vbeing constructed and arranged todischarge riddlings from said compartment and at the same time maintainsaid compartment sealed during operation.

8. In combination, a chain grate Stoker, a compartment located betweenthe upper and lower runs of said stolzer and communicating with thelower side of the upper run and comprising a plate located above thelower run of the chain grate, means for supplying air under pressure atone side of said compartment and grate, a rotary discharge memberllocated at the other side of said grate extending longitudinallythereof and sealed against said plate, said member being constructed andarranged to discharge riddlings from said compartment and at the sametime maintain said compartment sealed during operation. a

In testimony whereof We have hereunto signed our names.

CHRISTOPHER SAMUEL DAVY. ARTHUR SPYER.

